MIM Capacitor Testing in Semiconductor Devices
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Solution Overview
Problem
Conventional semiconductor devices face challenges in testing the reliability of MIM capacitors without increasing the chip area, as the testing capacitor requires a significant region, leading to inefficient use of space.
Innovation Solution
A semiconductor device design that includes a guard ring surrounding the circuit-forming region, allowing the MIM capacitor for testing to be formed above the guard ring, thereby utilizing a sufficiently large area without expanding the chip size, and utilizing a triple ring structure of seal rings to prevent moisture and ion penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a MIM capacitor for testing is formed in the same insulating interlayer film as the MIM capacitor for reducing IR drop, then the reliability testing can be performed, but the chip area increases
Solution Approach 1:
The patent utilizes the vertical dimension by forming the test MIM capacitor in a lower insulating interlayer film while the functional MIM capacitor is in the upper insulating interlayer film. This three-dimensional arrangement allows both capacitors to coexist without increasing chip area, as they occupy different vertical spaces within the multi-layer insulating structure.
Solution Approach 2:
The patent segments the insulating interlayer structure into multiple distinct films at different heights. The test MIM capacitor is formed in a first insulating interlayer film while the functional MIM capacitor is formed in a second insulating interlayer film located above it. This segmentation allows independent placement of testing and functional components without spatial conflict.
2Reliability
If a sufficiently large region is allocated for forming the MIM capacitor for testing, then the reliability testing effectiveness is improved, but the chip area increases
Solution Approach 1:
The patent resolves this contradiction by moving the test MIM capacitor to a lower vertical level in the insulating interlayer structure. This vertical relocation provides access to unused space in the lower insulating interlayer film, allowing the test capacitor to achieve sufficiently large area for effective reliability testing without consuming additional horizontal chip area.
3Object-affected harmful factors
If seal rings are formed to surround the circuit-forming region, then moisture and ion penetration is prevented, but the chip area is reduced
Solution Approach 1:
The patent segments the sealing function into multiple triple ring structures distributed at different vertical levels and positions. Instead of a single large seal ring that would significantly reduce circuit area, multiple smaller seal rings are placed strategically in different insulating interlayer films, providing comprehensive moisture and ion barrier protection while minimizing the total area occupied by sealing structures.
Data Source
AI summary
Disclosed is a semiconductor device which has a circuit-forming region. The semiconductor device has a semiconductor substrate, a plurality of insulating interlayer films, a guard ring, and a first MIM capacitor. The insulating interlayer films, which are stacked one upon another, are provided over the semiconductor substrate. The guard ring is formed in the plurality of insulating interlayer films and surrounds the circuit-forming region. The guard ring is separated from an insulating interlayer film including a topmost interconnect. The MIM capacitor is provided between the guard ring and the insulating interlayer film including the topmost interconnect.